This paper uses newly compiled data and a wide range of empirical analysis to assess the impact of government policies on agricultural exports and food production over the past two decades and across most sub-Saharan countries. While direct government control of marketing and prices of export crops has discouraged exports, disincentives created indirectly by overvalued currencies have been more damaging to agricultural supply in sub-Saharan Africa than in other regions. The rise of imported food to Africa has resulted mostly from factors that encourage consumers to eat imported food, and not from a failure of domestic production, as often assumed. These factors include overvalued currencies (which reduce the price of imported food), falling world food prices, high incomes during times of improved terms of trade, and increased urbanization (encouraged in part by policies of keeping farm prices low and concentrating government social spending in urban areas). Countries that have adopted and sustained policies to raise farm incentives have had better agricultural performance in the 1980's, on average, than those where policies continue to discriminate against agriculture.